| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a conventional three-phase PWM converter has difficulty of attaining easy and complete noise elimination and switching loss reduction. SOLUTION: Bridge circuits consisting of first to sixth main switches Q1 to Q6 are connected to three-phase AC terminals 1a, 1b, 1c. First to sixth main diodes D1 to D6 are connected in series with the respective main switches Q1 to Q6. A series circuit consisting of a first commutating reactor La and first and second regenerating diodes Da, Db, and a series circuit consisting of a second commutating reactor Lb and third and fourth regenerating diodes Dc, Dd are connected between a pair of DC terminals 2a, 2b of the bridge circuits. A first regenerating capacitor Ca is connected in parallel with the series circuit consisting of the first commutating reactor La and the first regenerating diode Da. A second regenerating capacitor Cb is connected in parallel with the series circuit consisting of the second commutating reactor Lb and the third regenerating diode Dc. Commutating switches Qa, Qb for controlling charging and discharging of first to sixth snubbing capacitors C1 to C6 are also provided.
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